Sanding to smooth out a newly painted wall

I just painted a couple walls and the last 2 sections dried rough/textured. I must of used too much paint or did something wrong.

My question is can I take a high grit sandpaper to smooth these 2 walls out? I would really hate to have to repaint these as it's a huge pia and very time consuming with the way life is right now. Any suggestions are very appreciated